The natural history of napkin-ring sign by coronary computed tomography angiography

Introduction: Despite their significance, the prevalence and the incidence of vulnerable plaques in coronary arteries, as well as their natural history, remain poorly known. Aim: To evaluate the prevalence, incidence and evolution of napkin-ring sign (NRS), and to establish factors associated with its presence, progression, or regression, in patients with suspected coronary artery disease (CAD). Material and methods: The study is based on a single-center prospective registry. Eighty-nine patients with suspected CAD underwent two computed tomography angiography (CTA) examinations within an interval of at least 24 months. High-risk plaque was defined by the presence of a low-attenuation area adjacent to the coronary lumen, surrounded by a ring of higher attenuation-NRS. Results: At the baseline 53 NRS were observed in 22 (25%) patients, 7 (8%) patients had single NRS and 15 (17%) had multiple NRS. After the follow-up period, there were 68 NRS in 32 patients. In 18 patients progression was observed with 23 additional NRS. Presence of single NRS and diabetes were independent predictors of NRS progression. Conclusions: The number of NRS plaque tends to increase over time in patients with suspected CAD. The progression may be predicted by the presence of diabetes or single NRS.